Communications operators are continuing to develop multiple play services which may include the provisioning of Internet access, television/video, and telephone services via a single broadband connection. Communications traffic at network edges is generally increasing over time due to the rising demand for such services by business and residential customers. This rising demand places an increasing requirement on the necessary bandwidth to deliver those services.
Access networks and infrastructures are also required to evolve over time to allow for such an increasing bandwidth need, and to deliver services at a lower cost per bit than the current cost. Future scalability of networks is also an important factor when designing new network infrastructures because the number of users and individual bandwidth requirements generally increases over time. Furthermore, the number of users changing their communications service provider also generally increases over time. The current trend in communications network design is to deploy optical fibre closer to the user, know as Fiber-To-The-Home or Business, via long reach networks such as Gigabit-capable Passive Optical Networks (GPONs).
It is also known to use a Wavelength Division Multiplexing Passive Optical Network (WDM-PON) to provide users with communications services. Performing WDM allows multiple different wavelengths carrying data to be transmitted via a single optical fibre. A typical WDM-PON comprises an Optical Line Terminal (OLT) at a central office premises, an optical wavelength splitter near the central office premises, and a series of Optical Network Units (ONUs) or Optical Network Terminals (ONTs) near the end users. Such a WDM-PON is considered to be passive because the optical transmission has no power requirements once an optical signal is travelling through the network section connecting the ONT or ONU to the OLT.
It is desirable to unbundle wavelengths with the known WDM-PONs to allow multiple communication service providers to provide communications services to different users over the same network infrastructure. Typically such unbundling is achieved by a telecommunications engineer visiting the OLT at the central office premises to physically reconfigure the OLT. Such physical reconfiguring can only be performed once the different operators have agreed in advance which wavelengths they should use. Unbundling is thought to be an important concept because it drives the growth of communications services and allows the communications network to grow and develop over time. Furthermore, unbundling is often a regulatory requirement to improve competition in the supply of communications service.
A communications network such as a WDM-PON can be expensive to install and maintain. Providing for the future scalability of the network may also be expensive particularly where additional optical fibre is required to be deployed in an urban environment. A significant driver in the design of future networks is to allow for future scalability at an appropriate cost whilst maintaining simplicity of use and deployment.